ideally, you'll want ones that are mana free, like Viscera Seer, Ashnod's Altar or Goblin Bombardment
Activate only as a sorcery." You can tap any untapped creature you control to convoke a spell, even one you haven't controlled continuously since the beginning of your most recent turn
Five-Color Reanimator (1 player): After discarding Atraxa, Grand Unifier to Fable of the Mirror-Breaker, she can be returned to the battlefield with Goryo's Vengeance and, ideally, blinked by Ephemerate
Its a bit naff, but its just the way of things
I prefer the interpersonal action of trading cards with another human being to just buying cards straight-up online and have acquired some truly excellent stuff over my 2+ years using this site
(9/22/2011) If the defending player controls no creatures when Grimgrin attacks, the last ability will be removed from the stack and have no effect